Electric switch



May 9,'1950 E. M. soRENG ETAI. 2,506,653

ELECTRIC SWITCH Filed sept. 19, 1946 s sheets-sheet 1 5 Edgar M 5mm E.M. SORENG El' AL ELECTRIC .SWITCH Filed sept. 19, 194e 3 Sheets-Sheet 2May 9, 1950 E. M. soRENG ETAL '2,506,653

ELECTRIC SWITCH Filed Sept. 19, 1946 3 Sheets-Sheet 3 l C* EDQEITMEcu-'En Laddze A Ean a H dz YF Patented May 9, 1950 ELECTRIC SWITCHEdgar M. Soi-eng, Laddie A. Sanda, and Hardin Y. Fisher, Chicago, Ill.,

assignors to Soreng Manufacturing Corporatior` Chicago, Ill., acorporation of Illinois Application September 19, 1946, Serial No.698,060

4 Claims.

This invention relates to electric switches, and

y refers more particularly to switches of the change-over type having asingle actuator and providing for the selective completion of one ormore electrical circuits or combinations thereof.

It is a general object of this invention to provide an improved electricswitch which is particularly well adapted for use as a change-overcontrol switch for the burners or hot plates of electric ranges.

Another object of this invention resides in the provision of a new andnovel switch of the character described having a single rotatableactuator and an unusually compact and eiiicient arrangement ofstationary and movable contacts controlled by said actuator forselectively completing a variety of different circuit connections.

Another object of this invention resides in the provision of anunusually simple switch of the character described wherein the switchparts cooperate with each other to secure the several components intheir proper positions with a minimum of fastening means.

Another object of this invention resides in providing a cam operatedswitch having a plurality of adjacent cams with movable contactorscapable of lbeing arranged closely together without interfering withindividual actuation of the contactors.

Still another object of this invention resides in the provision of a camoperated change-over switch of the character described having a readilyremovable end closure which accommodates and removably secures detentmeans defining the several operative positions of the switch.

A further object of this invention resides in the provision of a stampedterminal and an improved manner of attaching stationary switch contactsthereto.

With the above and other objects in view which will appear as thedescription proceeds, this invention resides in the novel construction,cornbination and arrangement of parts substantially as hereinafterdescribed, and more particularly deiined by the appended claims, itbeing understood that such changes in the precise embodilment of theherein-disclosed invention may be made as come within the scope of theclaims.

The accompanying drawings illustrate one complete example of thephysical embodiment of the invention constructed in accordance with the-best mode so far devised for the `practical application of theprinciples thereof, and in which:

Figure 1 is a perspective view of the completely assembled switch ofthis invention looking at the front of the switch;

Figure 2 is a `perspective view of the switch of this invention showingsome of its parts disassembled but in the proper order of theirassembly;

Figure 3 is a sectional view of the switch of this invention, takenalong the line 3-3 in Figure 4;

Figure 4 is a cross sectional view of the switch taken along the line4-4 in Figure 3;

Figure 5 is a cross sectional View through the switch taken along theline 5-5 of Figure 3;

Figure 6 is a perspective view of one of the switch terminals of thisinvention showing a movable contacter mounted thereon;

Figure 7 is an exploded perspective view of one of the terminals of theswitch of this invention illustrating the improved manner of securing astationary contact thereto;

Figure 8 is a perspective View of a portion of one of the fixedterminals, showing the stationary contact secured thereto; and

Figure 9 is a circuit diagram showing how the switch of this inventionmay be employed as a control switch for a hot plate of an electricrange.

Figure l0 is a view showing the indexing cam and its associatedspring-like members.

Referring now more particularly to the accompanying drawings, in whichlike numerals designate like parts throughout the several views, thenumeral I designates generally the housing for the switch of thisinvention. The housing has a rear wall 2, which forms a terminal head,and side walls 3 substantially perpendicular thereto and cooperatingtherewith to define a box-like case having an open front. The case ispreferably molded as a unit from insulating plastic, and has its openfront enclosed by an insulating plate 4. The plate is of a size andshape to be received within the mouth of the case to iill the same andrests on ledges 4 on the inner surfaces of two opposite side walls ofthe housing spaced inwardly from the front of the case a distancecorresponding to the thickness of the plate so that the plate liessubstantially ush with the outer edges of the side walls.

A rectangular `cover plate 5 preferably made as a sheet metal stampingis secured over the exterior 'of the insulating plate 4 against theouter edges of the housing side wall in any suitable manner.

In the present instance, two opposite side walls of the housingareindented to provide external wells 6 opening to the back and sides ofthe housing with the bottom of the wells located 'a short distanceinwardly from the front edges of the side walls.

The actuator or cam shaft 9 of the switch is mounted from the switchhousing for rotation on a xed axis substantially centrally of thehousing interior and normal to the terminal head 2. The inner end of theshaft is rotatably journalled in a well I in the inner face of theterminal head, while the outer end of the shaft, which projects throughthe plate 4 and cover 5 to have the usual knob mounted thereon, isjournalled in a flanged aperture i I in the cover 5.

A number of axially adjacent cams I3, in the present switch four, arecarried by the actuating shaft 9 at its inner end portion to rotatetherewith. These cams are preferably formed from insulating plastic,such as Bakelite, molded as a unit directly onto the metal shaft 9.

Terminal strips I4, of a number determined by the number of circuits tobe controlled by the switch, are arranged along a pair of opposite sidewalls 3 of the housing and extend in the direction of the shaft axis. Inthe present instance, the switch is shown provided with one group I4' offour terminal strips TI to T4, inclusive, arranged in a line along oneside wall of the housing and another group I4." of three terminal stripsT5 to T'I, inclusive, arranged in a line along the opposite side wall ofthe housing. The lug or hook-up ends I5 of all of the terminal stripsexcept T1 project through substantially close fitting slots I6 in theterminal head 2 to be exposed at the back of the switch and provide forsecuring electrical connections thereto. The remaining terminal strip T1has a medial right angle bend, and its lug or hook-up end projectslaterally through a suitable slot in the adjacent side wall of thehousing for line hook-up.

The terminal strips I4 are preferably formed of strip brass, and two ofthe group I4', namely TI and T3, are preferably straight and haveshoulders IB thereon provided by a small lug struck outwardly from thestrip as seen in Figure 6. This shoulder abuts against the inner side ofthe terminal head to define the extent to which the lugs I5 project atthe back of the switch. Shoulders I8' are formed on the terminal stripsT2, T4, T5 and T6 by a pair of opposite perpendicular bends which serveto offset the lugs I5 from the bodies of the strips, thus providingadequate clearance between the lugs I5 at the back of the switch andprecluding the possibility of short circuiting of the bare ends of thewires connected to them.

The terminal strip T1, as stated, has its lug I5 bent at right anglesfrom its body to project through the adjacent side wall of the switch,and this lug rests directly on the inner face of the terminal head. Aspur (not shown) projects from the strip T'I into a suitable cavity inthe head 2 to preclude inward displacement of the strip T1 except bytilting it to withdraw said spur from the cavity.

A pair of insulating strips I9 extends across the front of the housingover the forward ends of the terminal strips. These insulating strips I9are supported on ledges I1 on the side walls of the housing spacedinwardly from the ledges 4' a distance equal to the thickness of thestrips I9, so that the plate 4 rests thereon as well as on its ledges4', with the strips secured in position by the insulating plate 4.

Slots in the insulating strips I9 receive lugs d 2 I, protruding fromthe forward ends of the terminal strips, and cooperate with the slots I6in the terminal head 2 to hold the terminal strips I4 securely in theirproper positions within the housing. Shoulders 22 at the forward end ofthe terminal strips it abut againstthe inner .surfaces of the insulatingstrips to prevent endwise movement of the terminal strips within thehousing.

Each of the strips T5, T6 and T'l has a stationary contact 23 securedthereto (see Figure 7) For this purpose a pair of closely adjacentnotches 24 are cut or otherwise formed in one side edge of each of theseterminal strips, with the edge portion separating the notches forming ineffect a rivet 25. A substantially rectangular strip 26 of a conductivecontact metal, such as silver, having a central aperture 25' therein, isreceived snugly in the notched portion of the terminal strip with therivet 25 passing through the aperture 25' and peened-over onto thecontact strip to rivet the same to the side edge of the terminal strip,with the strips sov connected perpendicular to one another.

The rectangular pieces 25 thus form a pair of contact surfaces, atopposite sides of their peenedover lugs or rivets 25, for the terminalposts T5, T6 and Tl, designated I and C2, C3 and Cd, and C5 and C6,respectively.

In the switch shown, the contacts 26 on the posts T5 and T6 face eachother, while the contact 26 on the post Tl faces the post T6.

There are four movable contactors which are identified by the numeralsMI, M2, M3 and M4 in the switch illustrated. The contactors are formedfrom strips of flexible conductive material, such as spring brass, andare of a length to extend substantially across the interior of thehousing I between terminal strips of the two groups I4 and id" therein.

All of the contactor arms have an attaching end 28 bent atwise at rightangles to the arm to provide for securement of each arm to one of theterminal posts. These attaching ends are secured iiatwise against onefiat face of their terminal posts, as by rivets 28', with the at sidesof the arms parallel to the lengths of the post.

A contact 29, such as a silver rivet, is preferably secured to the freeend of each contactor arm for engagement with the fixed contacts 23 onthe terminal posts.

The medial portion of each contactor arm is provided with a longitudinalslit 29', and the material on either side of the slit is bent outwardlyto opposite sides of the strip to form a camfollower 3D and a stiiener3|.

In the switch shown, the contactors MI and M2 are carried by theterminal posts TI and T2, respectively, and project in the samedirection across the housing from between these posts, at one side ofthe cam axis, so that the contact end of the arm MI lies between and iscooperable with the stationary contact surfaces CI and C3 on the postsT5 and T6, respectively, and so that the contact end of the arm M2 liesbetween and is cooperable with the stationary contact surfaces C2 and C4on the posts T5 and T6, respectively. The contactors M3l and M4 arecarried by the terminal posts T4 and T6, respectively, and project inopposite directions across the housing at the other side of the camaxis. This disposes the contact end of the arm M3 adjacent to thestationary contact surface C5 for cooperation therewith, and positionsthe contact end of the arm M4 between the adjacent edges of the posts T3and T4 for cooperation with the edge C6 of the post T3.

It will thus be seen that the movable contactor arms are arranged inpairs at opposite sides of the cam axis, and it is important to notethat arms are mounted in such positions along the lengths of theirrespective posts that no two arms lie in the same transverse plane ofthe housing. In other words, the contactor arms of each pair, thoughspaced equal distances apart in the direction of the cam axis, arestaggered with respect to the contactor arms of the opposite pair.

It is to be understood that while two movable contactors 21 have beenshown arranged on either side of the cam shaft 9, this arrangement ismerely illustrative, since any desired grouping or arrangement ofcontactors and terminal post may be employed.

The movable contactors 21 are biased toward the cam axis to have the'rcam followers 30 bear against the peripheries of their respective camsunder a degree of spring pressure. Hence, upon rotation of the cams whenthe shaft 9 is turned, the free contact ends of the movable contactors21 will be carried flatwise into and out of engagement with one or theother of their cooperating stationary contacts.

Since the cam follower' 30 of each movable contacter 21 is only half aswide as the strip from which the contactor is formed, and since the armsare in staggered relationship, it will readily be seen that relativelynarrow cams may be used to advantage for the achievement of a relativelycompact, shallow switch housing.

The cover plate is stamped with a shallow well I3I, preferablysubstantially rectangular in shape, and medially of the cover 5, withthe well opening inwardly toward the switch housing. A pair of elongatedflexible detent strips 32 is disposed in the well along a pair ofopposite sides thereof with their ends received in the corners 33 of thewell, and these strips are held in place in the well by the insulatingplate 4. The medial portions of the strips 32 are bent toward each otherto form opposite detent nubs 34 which yieldingly simultaneously engagein the tooth spaces of a substantially gear shaped indexing cam 35 onthe shaft 9 to define detents at each of the operative positions of theswitch.

Although the indexing cam 35 is situated in the well at the exterior ofthe plate 4, it is preferably molded integrally with the cam unit I3. Itwill be readily seen that the strips 32 are secured in place bycompression between the indexing cam 35, acting upon their medialportions, and the corners 33 of the well ISI, against which the ends ofthe strips react.

As may `be seen from Figures 4 and 5, the movable contactors 21 may bearranged with their free ends at either side of the housing, or at bothsides thereof; and some of the terminal posts I4 may carry both astationary contact 23 and a movable contact 21. The cams I3 must, ofcourse, be designed to flex the contactors 21 accordingly. It will beunderstood that the cams may be constructed to aord full 360 rotation ofthe cam shaft 9 or some limitation may be placed on its movement byappropriate means, to fulfill the requirements of the particularinstallation of the switch. It is thus possible to adapt the switch ofthis invention to provide a large number of combinations andpermutations of circuit connecf tions, suitable for a wide Variety ofapplications.

With the particular switch shown, the number and arrangement of theswitch elements, including the cams I3, is such as to provide a total ofseven different energizing circuits for a pair of resistances RI and R2comprising the heating elements of a single hot plate for an electricrange, and in addition an off position for the plate Inasmuch as theswitch thus has eight positions, arrived at successively by turning theshaft 9 through 360, it will be noted that the indexing cam is providedwith eight equi-spaced tooth spaces for engagement by the detentsprings. Referring to Figure 9, which is a circuit diagram for the eightposition switch hereinbefore described, the letter N designates theneutral or v. line of a 110-220 volt alternating current power supply.The letters LI and L2 designate the two hot or 220 v. lines of the powersupply.

In wiring the switch, the hot power lines Ll and L2 are adapted 'to beconnected to the lugs of the terminal posts T5 and T1 respectively,while the neutral or 110 lead N is adapted to be electrically connectedto the lug of the terminal post T6.

One end of the resistance RI is adapted to be connected to the lug ofthe terminal post TI through a conductor 5G, and one end of theresistance R2 is adapted to be connected to the lug of the terminal postT2 by means of a conductor 5I. The opposite ends of the resistances RIand R2 are joined by a conductor 52 which connects through anotherconductor 53 to the lug of the terminal post T.

In the diagram, the switch is shown in the off position and it is to beunderstood that the cams for each of the movable contactors 21 aredesigned to complete a total of seven diilerent energizing circuits forthe resistances RI and R2 upon rotation of the actuator of the switchthrough 360, with each operative condition of the switch defined by theengagement of the detent nubs 34 and a pair of diametrically oppositetooth spaces in the gear-like indexing cam 35.

By way of illustration, rotation of the actuator to carry the camassembly I3 from a switch off position, illustrated in the diagram, to arst operative setting causes the cams to effect engagement of themovable contacts M and M2 with the stationary contact surfaces CI andC4, respectively, carried by the terminal posts T5 and T6, respectively.This irst operative position of the switch constitutes a low heatcircuit for the resistances RI and R2, with the circuit completed fromthe power lines N and LI to cause a current of 110 volts to flowserially through the two resistances.

Simultaneously with the completion of the series energizing circuit forthe resistances RI and R2, the cam for the contactor M4 eifectsengagement thereof` with the edge C5 of the terminal post T3 to completean energizing circuit for the pilot lamp 55 through a conductor 55leading from the lug of the terminal post T3 to one side of the filamentof the lamp and through another conductor 51 leading from the other sideof the iilament of the lamp to the lug of the terminal post T1, so thatthe pilot light is energized by the 110 volt circuit provided by thelines L2 and N.

From Figure 4 it will be apparent that the cam for the pilot lightcontactor M4 is shaped so as to bre-ak the energizing circuit for thepilot light only in the off position of the switch and to maintain theenergizing circuit at al1 other positions of rotation of the actuator.Because of the infrequent breaking of the pilot light circuit and thefact that the light draws a relatively low current, the terminal post T3and the contactar 7 Ml have not been provided with silver contacportions; however, if desired, these may be used.

As will be apparent from the diagram, the conductor i may be connectedto either of the terminals T5 or T1 for the power lines LI and L2.

While the exact sequence in which the remaining energizing circuits areestablished for the resistances Rl and R2 is optional, rotation of theactuator to the next operative position of the switch may, for the sakeof illustration, engage the movable contactor M3 with the contactsurface C5 carried by the terminal T1, leaving the contactors MI and M2engaged with the stationary contacts CI and C4. In this second operativeposition of the switch, the power line L2 is paired with each of thepower lines Li and N to provide individual 220 volt and 110 voltenergizing circuits for the resistances Rl and R2 respectively.

The cams for the movable contactors Ml and M2 may be so formed as toeffect reversal of the positions of these contactors upon rotation ofthe actuator to the third operative position 0f the switch, bringing themovable contactor MI into engagement with the stationary contact C3 andthe movable contactor M2 into engagement with the stationary contact C2.Reversing of the positions of the removable contacts Ml and M2 in thismanner eiects a reversal of the energizing potentials for theresistances RI and R2 to produce a third heating value for the hotplate.

A fourth heating value for the hot plate may be readily obtained byrotation of the actuator to the next operative position of the switch ifthe cam for the movable contactor M2 is formed to disengage the samefrom the stationary contact C2 and reengage it with the stationarycontact C4, without altering the positions of the remaining contactors.This leaves the resistance Rl energized by a 110 volt current andestablishes a 110 volt energizing circuit for the resistance R2 as well.

The fth heating value for the hot plate is obtained by further actuationof the switch to its sixth position in which the cams for the movablecont/actors Ml and M2 effect reversal of the preceding positions ofthese contactors so as to bring the same into engagement with thestationary contacts Cl and C2, respectively. In this position of theswitch the conductors 50 and 5I connect with the power line LI, and a220 volt circuit is completed through both resistances Rl and R2 bymeans of the conductors 52 and 53 and the closed contactor M3 to givethe highest heating value of the hot plate.

The sixth operative position of the switch may be one which produces asimmer heating value for the hot plate. This is readily accomplished bymeans of the cams for the movable contactors Ml and M2 which in thisposition place the contactor M2 in a neutral position, disengaged fromeither of its cooperating stationary contacts C2 and C4, and reengagethe. contactor MI with its stationary contact C3. In this operativeposition of the switch the resistance element Rl is energized by acircuit including the power lines L2 and N, while the resistance R2 isout of the circuit.

In the nal operative position of the switch, obtained by rotation of theactuator to the eighth position, the cam for the contactor MI may beformed to effect movement of the contactor MI to a, neutral position,entirely disengaged from its cooperating stationary contacts CI and C3,with the cam for the contactor M2 effecting movement thereof intoengagement with the stationary contact C2. This setting of the switchprovides for energization of the resistance R2 by a 220 volt energizingcircuit and disconnects the resistance RI from' the power lines.

Rotation of the switch actuator to the next position dened by thegear-like detent cam disengages all of the movable contacts Mi' to M4,inclusive, from their cooperating stationary contacts to place theswitch once again in the oiT position.

It is also to be understood that, without the addition of any moremovable contactors or stationary contacts, two additional heating valuesmay be obtained merely through the provision of suitably shaped cams forthe movable contactors MI and M2, along with a ten station detent cam.In other words, individual 220 volt energizing circuits may be completedfor each of the resistances RI and R2 by eiecting separate andsuccessive engagement of the movable contactors MI and M2 with theircooperating stationary contacts Cl and C2. If these latter two stationsare added it will be appreciated that but one detent spring strip can beused because the tooth spaces of the ten tooth detent cam 'will not bediametrically opposite one another.

It will be seen from Figure 9 that theswitch of this invention requiresfewer movable contactors than the conventional switch to eiect the samecontrol of an electric range burnen From the foregoing description,taken together with the accompanying drawings, it will be readilyapparent that this invention provides an improved and greatly simplifledmultiple contact electric switch of the type suited for use as achange-over switch for the burners or bot plates of electric ranges.

What we claim as our invention is:

1. A contactor for a cam operated switch comprising: a relatively atelongated spring blade adapted to have one end rigidly secured to astationary support so that its opposite end is free to be exed iiatwisein opposite directions toward and from a stationary contact of theswitch; contact means on the blade at the free end thereof so as to bemovable therewith into and out of engagement with the stationary contactupon exure of the blade by engagement of a cam with the medial portionthereof; and said blade having a longitudinal slit at its medialportion, with the material on each side of said slit bent outwardly fromthe plane of the blade in opposite directions to provide a substantiallyrigid cam follower at one side of the blade and a reinforcing portion atthe opposite side of the blade, said reinforcing portion also beingadapted to be used as a cam follower so that the blade may be installedwith either of its sides adjacent the cam.

2. A contactor for a cam operated switch comprising: an elongated exibleblade adapted to be rigidly secured at one end to a stationary supportfor fiexure of its opposite end toward and from a stationary contact ofthe switch by means of a rotatable cam engageable with the medialportion of the blade, said blade being formed from a strip of springstock having a longitudinal slit in a mid-portion thereof; a camfollower integral with the blade and projecting to one side thereofformed by oisetting the portion of the blade at one side of the slit;and an alternate cam follower projecting from the other side of theblade formed by offsetting the portion of the blade at the opposite sideof the slit and thereby enabling the blade to clear a cam axiallyadjacent to that with which the first named cam follower is engaged.said two offset portions resulting in foreshortening of the blank fromwhich the blade ls formed so that said offset portions havesubstantially the same metal thickness as the remaining portions of theblade, and said offset portions cooperating with each other to stiffenthe medial portion of the blade.

3. In an electrical switch of the type having a housing and whereinrotation of a single rotatable actuating shaft projecting fromthehousing selectively effects completion of different electricalcircuits: a cam unit in said housing fixed on said shaft to rotatetherewith and having a plurality of closely adjacent peripheral camsurfaces thereon; a plurality of spring blade switch contactors each xedat one end with respect to the housing and lying crosswise of the shaftaxis with one nat face facing the periphery of the cam unit and biasedtoward engagement therewith, each of said blades having a width such asto overlie a pair of axially adjacent cam surfaces on the unit and eachblade having a longitudinal slit in a portion thereof opposite the camunit; a cam follower integral with each blade riding on the periphery ofone of said cam surfaces which the blade overlies and formed byonsetting the side edge portion of the contacter blade at one side ofthe slit a distance to one side of the plane of the blade; andreinforcing means for said slit portions of the blades formed byoffsetting the side edge portion of each blade at the other side of theslit therein a distance to the opposite side of the plane of the blade,said offset reinforcing portions of the blades -providing clearancebetween each blade and the other of the cam surfaces which the bladeoverlies.

4. In an electrical switch of the type wherein rotation of a singlerotatable actuating shaft selectively effects completion of differentelectrical circuits: a plurality of axially adjacent cams fixed on saidshaft to rotate therewith; a plurality of relatively fixed terminalposts spaced from the cam axis and extending lengthwise thereof atopposite sides of the cam axis; a plurality of bladelike contactorslying crosswise of the shaft axis. each having its middle portionresting on the periphery of one of said cams and its opposite endsdisposed adjacent to terminal posts at opposite sides of the shaft axis,with contactors on opposite sides of the shaft disposed in common planesnormal to the shaft axis, each of said contactors being substantiallywider than the cam with which it cooperates and having a longitudinalslit in a mid-portion thereof; a cam follower integral with thecontactar and projecting to one side thereof formed .by offsetting theportion of the contacter blade at one sideof the slit; stiffening meansfor the medial portion of the contactor projecting to the other side ofthe blade formed by offsetting the portion of the blade at the oppositeside of the slit a distance sufficient to clear the periphery of the camaxially adjacent to that with which the contactor cooperates; and meansmounting each contactor by one end thereof on terminal posts adjacent tothe ends of the contactors with the contactors arranged at oppositeperipheral sides of the cams so that rotation of the cams effectsmovement of the opposite ends of the contactors toward and fromengagement with contact surfaces on terminal posts adjacent thereto.

EDGAR M. SORENG. LADDIE A. SANDA. HARDIN Y. FISHER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,317,203 Lynch Sept. 30, 19192,059,712 Schellenger Nov. 5, 1936 2,203,224 Kimball June 4, 19402,243,566 Kimball May 27, 1941 2,317,967 Tuttle Apr. 27, 1943 2,350,967Nunes June 6, 1944

